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Walmir Ribeiro de Carvalho Steel Silva Vasconcelos Osvaldo Ryohei Kato Carlos José Bispo Capela Débora Cristina Castellani 《Agroforestry Systems》2014,88(2):357-368
The current expansion of the oil palm (Elaeis guineensis Jacq.) in the Brazilian Amazon has mainly occurred within smallholder agricultural and degraded areas. Under the social and environmental scenarios associated with these areas, oil palm-based agroforestry systems represent a potentially sustainable method of expanding the crop. The capacity of such systems to store carbon (C) in the soil is an important ecosystem service that is currently not well understood. Here, we quantified the spatial variation of soil C stocks in young (2.5-year-old) oil palm-based agroforestry systems with contrasting species diversity (high vs. low); both systems were compared with a ~10-year-old forest regrowth site and a 9-year-old traditional agroforestry system. The oil palm-based agroforestry system consisted of series of double rows of oil palm and strips of various herbaceous, shrub, and tree species. The mean (±standard error) soil C stocks at 0–50 cm depth were significantly higher in the low (91.8 ± 3.1 Mg C ha?1) and high (87.6 ± 3.3 Mg C ha?1) species diversity oil palm-based agroforestry systems than in the forest regrowth (71.0 ± 2.4 Mg C ha?1) and traditional agroforestry (68.4 ± 4.9 Mg C ha?1) sites. In general, no clear spatial pattern of soil C stocks could be identified in the oil palm-based agroforestry systems. The significant difference in soil carbon between the oil palm area (under oil palm: 12.7 ± 2.3 Mg C ha?1 and between oil palm: 10.6 ± 0.5 Mg C ha?1) and the strip area (17.0 ± 1.4 Mg C ha?1) at 0–5 cm depth very likely reflects the high input of organic fertilizer in the strip area of the high species diversity oil palm-based agroforestry system treatment. Overall, our results indicate a high level of early net accumulation of soil C in the oil palm-based agroforestry systems (6.6–8.3 Mg C ha?1 year?1) that likely reflects the combination of fire-free land preparation, organic fertilization, and the input of plant residues from pruning and weeding. 相似文献
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Daisuke FUKUI Masashi NAGANO Ryohei NAKAMURA Gen BANDO Shinichi NAKATA Masao KOSUGE Hideyuki SAKAMOTO Motozumi MATSUI Yojiro YANAGAWA Yoshiyuki TAKAHASHI 《The Journal of reproduction and development》2013,59(5):491-495
Artificial insemination (AI) can help to avoid inbreeding and genetic degeneration
for sustaining genetically healthy populations of endangered species in captivity.
Collection of a sufficient quantity of viable sperm is an essential first step in the
AI process. In the present study, we examined the effects of frequent
electroejaculation on semen characteristics in a Siberian tiger. We collected semen
in all 17 trials during 6 breeding seasons (6 years). The mean number of sperm and
the percentage of motile sperm were 294.3 ± 250.2×106/ejaculate and 82.4 ±
11.4%, respectively. The number of motile sperm tended to increase during frequent
electroejaculation in the same breeding season. Semen collection by
electroejaculation can be performed effectively up to the fourth sequential
ejaculate, which contained the most sperm in the study. In conclusion, frequent
collection of sperm by electroejaculation from tigers may be effective for collection
of a large number of motile sperm. 相似文献
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Inoue K Ohashi E Kadosawa T Hong SH Matsunaga S Mochizuki M Nishimura R Sasaki N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1437-1440
Four canine melanoma cell lines were established from the subcutaneous, oral gingival and mucosal melanoma tissues at the primary and metastatic sites. These cell lines were designated as CMeC-1, CMeC-2, KMeC and LMeC. The cells were spindles in shape, similar to that of primary tumor cells. The doubling times of these cells ranged from 34.1 +/- 5.61 to 57.9 +/- 3.28 hr and their chromosome number ranged from 46 to 80. When transplanted into nude mice, CMeC-1 and LMeC produced tumors, whereas CMeC-2 and KMeC did not. The morphology of the tissue formed by xenotransplantation of these cells was similar to their primary tumors. 相似文献
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Significance of tumor-infiltrating immune cells in spontaneous canine mammary gland tumor: 140 cases
Saeki K Endo Y Uchida K Nishimura R Sasaki N Nakagawa T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(2):227-230
The numbers of tumor infiltrating T lymphocytes, B lymphocytes and antigen presenting cells were evaluated in an immunohistochemical manner in 140 canine spontaneous mammary gland tumor (MGT) tissues. As a result, we found a statistically significant increase in the number of intratumoral T lymphocytes (23.2 ± 23.8) in the malignant MGT group (n=51) compared with the benign MGT group (14.0 ± 16.0, n=89; P<0.05). Moreover, the high T lymphocyte infiltration in the malignant group correlated with poor prognosis in multivariate analysis (P<0.05). This study indicated the relationship between increased infiltrating T lymphocytes and canine MGT malignancy. 相似文献
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Ohmori K Kawarai S Yasuda N Tanaka A Matsuda H Nishimura R Sasaki N Tsujimoto H Masuda K 《Veterinary immunology and immunopathology》2008,126(1-2):43-53
Gain-of-function mutations in the proto-oncogene c-kit have been considered the molecular mechanism of neoplastic proliferation of mast cells. However, the importance of c-kit gene mutations is not well evaluated in canine mast cell tumors (MCTs). In the present study, we established and characterized a mast cell line, HRMC, derived from a dog with MCT. We also examined c-kit mutations in HRMC cells and assessed an inhibitory effect of a tyrosine kinase inhibitor, STI571, on HRMC cells. HRMC cells had cytoplasmic metachromatic granules, chymase and tryptase, and expressed both KIT and FcepsilonRI on the cell surface. HRMC cells contained histamine and released beta-hexosaminidase through FcepsilonRI cross-linking and calcium ionophore stimulation. Nucleotide sequence analysis demonstrated no mutations in an open reading frame of c-kit cDNA and genomic DNA of the juxtamembrane domain of c-kit in HRMC cells. STI571 did not show any inhibitory effects on the proliferation of HRMC cells. These findings clearly demonstrated the existence of c-kit mutations-independent neoplastic canine mast cell proliferation. The growth factor-independent mast cell line established in this study might be valuable to explore novel mechanisms of c-kit mutations-independent neoplastic proliferation of mast cells in dogs. 相似文献
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Ohmi A Tsukamoto A Ohno K Uchida K Nishimura R Fukushima K Takahashi M Nakashima K Fujino Y Tsujimoto H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(1):59-64
Medical records of dogs with colorectal polyps were retrospectively reviewed, and clinical presentation of inflammatory colorectal polyps in miniature dachshunds was evaluated. Of 33 dogs found to have colorectal polyps, miniature dachshunds were markedly over-represented with 16 dogs (48%), of which 12 (75%) were found to have inflammatory polyps. Multiple polyps localized between the rectum and the descending colon was the most common finding in miniature dachshunds with inflammatory polyps. Twenty dogs (80%) out of 25 miniature dachshunds with inflammatory colorectal polyps responded to immunosuppressive therapy using prednisolone and cyclosporine. The results of this study indicate that miniature dachshunds are predisposed to develop inflammatory colorectal multiple polyps, for which immunosuppressive therapy may be a treatment option. 相似文献
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In neurons, individual dendritic spines isolate N-methyl-d-aspartate (NMDA) receptor-mediated calcium ion (Ca2+) accumulations from the dendrite and other spines. However, the extent to which spines compartmentalize signaling events downstream of Ca2+ influx is not known. We combined two-photon fluorescence lifetime imaging with two-photon glutamate uncaging to image the activity of the small guanosine triphosphatase Ras after NMDA receptor activation at individual spines. Induction of long-term potentiation (LTP) triggered robust Ca2+-dependent Ras activation in single spines that decayed in approximately 5 minutes. Ras activity spread over approximately 10 micrometers of dendrite and invaded neighboring spines by diffusion. The spread of Ras-dependent signaling was necessary for the local regulation of the threshold for LTP induction. Thus, Ca2+-dependent synaptic signals can spread to couple multiple synapses on short stretches of dendrite. 相似文献